Abstract: Objectively analyzing the impact of regional integration on tourism industry efficiency holds significant implications for promoting the high-quality economic and social development of the Yangtze River Delta urban agglomeration. The entropy method, linear weighting method, and super efficiency Data Envelopment Analysis SBM model were employed to measure the level of integrated development and tourism industry efficiency, from 2008 to 2020. The study also utilized the spatial Durbin model to reveal the underlying relationship and spatial effects between the two. The study found that: (1) The level of regional integration increased from 0.304 in 2008 to 0.490 in 2020, showing a robust upward trend. A "high-southeast, low-northwest" pattern was presented. The "high-high" and "low-low" cluster aggregation characteristics was evident. (2) The tourism industry efficiency value showed a slightly fluctuating downward trend, with the trough point appearing in 2020. The spatial distribution exhibited an "east high, west low, and middle-high with north-south low" pattern. The number of cities with high efficiency gradually increased and expanded to the southeast. (3) The level of regional integration had a significant spatial spillover effect on tourism industry efficiency. Government regulation, urbanization level, level of informationization, degree of transportation convenience, degree of openness, and level of technological development all had positive direct effects on local tourism industry efficiency. Urbanization level and level of informationization had positive spillover effects on neighboring tourism industry efficiency, while government regulation and transportation convenience exhibited negative spillover effects.